Age-related macular degeneration (AMD) is a leading cause of visual impairment in the United States. Available evidence suggests that AMD is a complex disorder with a significant genetic component as well as potential environmental influences. In this collaborative study we propose to examine 3,000 members, ages 50 and older, of the Old Order Amish community in the Lancaster and Franklin counties area in Pennsylvania. We plan to detail the epidemiology of AMD in this population isolate in attempt to elucidate genetic factors which may confer susceptibility and predispose some Amish individuals and their families to develop AMD. All study participants agreeing to enroll and providing informed consent will undergo a complete, dilated eye examination during which digital stereo images of the macula and optic disc regions will be acquired. Study participants will also be asked to complete a brief questionnaire inquiring about personal exposures related to occupation, sunlight, and smoking. AMD will be determined by an independent reading of the digital fundus photographs by the University of Wisconsin Fundus Photography Reading Center according to the Age-Related Eye Disease Study's AMD classification scheme. As of July 2005, 970 Amish adults have been examined. Genetic sequencing of mutations in a region of complement factor H have been performed in a population-based sample of 820 individuals. The study is on-going.